Qsymia -- pronounced kyoo-SIM-ee-uh, according to Vivus Pharmaceuticals -- is the first new weight loss drug to reach market in 13 years. Vivus chose the name Qsymia after the FDA rejected a previous name, Qnexa.

It's an important day for people whose weight is destroying their health, says Sue Decotiis, MD, of New York's Manhattan Medical Weight Loss Physician, a practice specializing in obesity treatment. Decotiis has no ties to companies that make weight loss drugs.

"For us weight loss specialists, any new tool we can get our hands on is very exciting," Decotiis says. "We're not talking about the person who just needs to lose 10 pounds. We are talking about the patient who is obese or very overweight with related health problems."

Dramatic weight loss can come from lifestyle changes alone. Lifestyle change is hard for anyone, but obesity makes it harder. The body burns less and less fuel. Appetite increases. And exercise hurts.

"They get de-motivated quickly because they have no success," Decotiis says. "Doctors prescribe weight loss drugs knowing full well that any drug can have side effects or complications. But that is why it is put in the hands of a prescribing doctor, who will follow the patient carefully, monitoring for side effects and educating the patient."

Qsymia does have serious side effects. One of the most troublesome is that the drug can cause birth defects if taken during pregnancy. Women of childbearing age must confirm with their doctor that they are using 100% effectivebirth control before they can get a Qsymia prescription.

Other possible side effects include increased heart rate, suicidal thoughts or actions, and serious eye problems.

Qsymia Health Benefits

Michelle Look, MD, of San Diego Sports Medicine and Family Health Center, treated patients in the Qsymia clinical trials.

"We found that over the entire 52 weeks of the first trial, patients lost from 11% to 14% of their body weight," Look says. "But the most dramatic effect we saw was in patients who were pre-diabetic and were prevented from converting to diabetes -- and in patients who had diabetes who not only had lower blood sugar but whom we could take off several of their diabetes medications."

Look said many of the study participants volunteered because they had "really, really tried to reduce weight via diet and exercise" but failed over and over again.

"Obesity needs to be treated as the chronic medical disease it is," Look says. "This means putting people on medication, but we have not had an effective tool for treating people. Now, in addition to diet and exercise, we have a medical therapy."

Qsymia: Diet, Exercise Still Needed

Qsymia is not a diet in a bottle. The medication works only in combination with diet and exercise.

But taking the drug made it easier to cut calories and to become more active, says Gwen Barton. Barton, 57, a New York City resident, volunteered for one of the clinical trials that led to Qsymia approval. WebMD contacted Barton through Vivus' public relations firm.

"The diet got easier as I went along with the trial," Barton says. "I didn't have the appetite I did before, or all the cravings for sweets and stuff. And within a month or so I was losing 2 to 3 pounds a week or more."

The 5-foot-2 Barton weighed 210 pounds when she started taking Qsymia. Over the year-long study, she lost 50 pounds. Since the study ended, she hasn't been able to get the drug. She's now gained back 20 pounds.

"Now I am just so happy the drug is back," Barton says. "I've made my doctor appointment already."

Qsymia Cost

At first, Vivus expects few private or public insurance plans to pay for Qsymia prescriptions. While the company plans to work to get its drug added to formularies, most people likely will pay out of pocket.

The wholesale price of Qsymia -- that is, the price pharmacies will pay -- for a 30-day supply will be:

Low dose (3.75 mg phentermine/23 mg topiramate) -- $120.00

Recommended dose (7.5 mg/46 mg) -- $135.62

Three-quarter dose (11.25 mg/69 mg) -- $162.74

Top dose (15 mg/92 mg) -- $183.90

As part of a risk-reduction plan Vivus negotiated with the FDA, Qsymia will be available only to doctors who have completed a Qsymia provider-training program. The drug will be sold only through certified mail-order pharmacies. At this time, those pharmacies are CVS, Walgreens, and Kaiser Permanente (for Kaiser members only).